Hey guys, my '97 4.6 has developed a sound under the dash that sounds like rippling water. I'm thinking that it is trapped water from the AC condenser. Has anyone had the same problem, or can tell me how to drain it, if it is in fact water?

 

Its your heater core. My '98 4.6 did it and my '03 5.4 is starting to do it. What helped for a while in my '98 was getting the coolant system flushed with machine hook up at the oil change center. I think the passages in the heater core are so small that build up in the system collects there and gurgles after the engine is shut off.

 

Flushing your heater core itself then bleeding the system of air should do the trick. Or like cws said, coolant flush, since that will remove anything else in the system so it doesn't happen again (or at least not soon).

 

Normal sound, but, a coolant flush is never a bad idea, should be every 2-3 years done.